1. Field of the Invention
This invention relates to an anti-theft device for vehicles. In particular, this invention relates to a remote-controlled device that automatically deflates one or more tires of a vehicle when it is stolen.
2. The Prior Art
Vehicle theft is a large problem all over the world. Consequently, there have been many attempts to provide devices and systems that prevent theft or facilitate the recovery of a vehicle after it has been stolen. Theft prevention systems include sophisticated alarm systems and mechanical devices such as "the Club", which prevents the steering wheel from turning and is highly visible. Recovery systems such as "Lojack" use a radio transmitter to locate the stolen vehicle.
There have also been several attempts to provide systems that disable the vehicle's tires upon theft of the vehicle. One example is discussed in U.S. patent application No. 4,818,029 to Mourot et al., which discloses a tire deflating device that is activated by the centrifugal force of the wheel rotating. The device is applied to the wheel by the owner upon parking the vehicle, and is installed onto the tire valve. This device has the disadvantage that the owner may forget to remove the device and suffer a flat tire when the vehicle is driven. Other similar devices are shown in U.S. Pat. Nos. 4,375,200 to Bertani et al., and 3,910,221 to Aske et al.
Another device is shown in U.S. patent application No. 3,688,257 to Mann, which discloses an anti-theft device that operates using a solenoid valve to remove a plug in the tire. The device is connected to the ignition switch which energizes the solenoids and keeps the plug in place for normal operation of the car. If the car is started without turning the ignition switch, the solenoids are not energized and the tire rotation causes probes to strike and break against the plugs to deflate the tire. While this device is a useful anti-theft system, it does not have sufficient safety measures to ensure that the tires are not accidentally deflated by the owner. Furthermore, the solenoids are located on the exterior of the wheel and are highly visible to thieves.
A remote-controlled anti-theft system is disclosed in U.S. Pat. No. 5,533,589 to Critzer et al., which disables an electrical component of the vehicle upon activation. A remote controlled alarm that is set to activate upon motion of a vehicle wheel is disclosed in U.S. Pat. No. 4,947,151 to Rosenberger. This device does not disable the tire.
Other anti-theft tire devices are shown in U.S. Pat. No. 5,419,408 to Ellrodt et al., U.S. Pat. No. 3,661,115 to Rosenstein, and U.S. Pat. No. 5,611,408 to Abukhader. None of the devices shown in these patents are convenient or safe for the average consumer to use, and result in destruction of the tire upon activation.